In recent years, antibacterial/antiviral coating films have been applied to a wide variety of products as the awareness of hygiene concept and beauty in the living environment has increased. Generally in order to add antibacterial/antiviral properties to a coating film, it is a known method to form a coating film using a paint to which an effective amount a quaternary ammonium salt is added.
However, in the case of using an antibacterial/antiviral coating film in a member for wet area such as a kitchen sink or a faucet handle of a bathroom, the water resistance of the coating film is a problem. With regard to this, when a coating film to which a quaternary ammonium salt was added comes into contact with water, it is concerned that the quaternary ammonium salt dissolves out therefrom and the antibacterial/antiviral properties thereof are thus impaired. In order to solve this problem, an invention is described in Patent Document 1 that can suppress dissolution out of the quaternary ammonium salt from the coating film and can form an antibacterial/antiviral coating film exhibiting excellent water resistance by adding a polyvalent carboxylic acid to the paint together with a quaternary ammonium salt.
Incidentally, an acrylic melamine paint is often used as a paint for construction members, but it has been concerned that poor curing of the coating film occurs and a high surface hardness and high solvent resistance are not obtained when a quaternary ammonium salt is added to an acrylic melamine paint. In order to solve this problem, it is described in Patent Document 2 that it is possible to eliminate poor curing of the coating film caused by the addition of a quaternary ammonium salt by adding phosphoric acid as a curing accelerator of the coating film to the acrylic melamine paint together with a quaternary ammonium salt.
[Patent Document 1] Japanese Unexamined Patent Application, Publication No. 2015-67658
[Patent Document 2] Japanese Unexamined Patent Application, Publication No. 2013-71031